It has long been common for a bathtub alcove to have both a tub spout and a shower head. The shower head and spout commonly are both connected to the same single handle valve or set of hot and cold water valves. Furthermore, it is common to have a diverter valve mounted directly on the tub spout so that in one position water is allowed to exit through the tub spout and in the other position the diverter valve closes off the exit through the tub spout and forces water up through the shower riser to the shower head.
One of the common problems with such an arrangement between the shower head and tub spout is that there is no positive shut off to the shower head. Even when the diverter valve is positioned to direct water through the tub spout, sufficient pressure can build up within the shower riser leading to the shower head so water leaks through the shower head.
Previous attempts to prevent the leakage through the shower head have required an aspirator insert which was threaded into a bore of a fitting. One aspirator has side inlets so that a counterbore within the fitting is needed to receive water from the inlet port to pass about the aspirator to the side inlets. The water is then directed through a passage having a 90 degree turn and is jetted out through a downward facing exit into the tub spout pipe.
Another aspirator attempting to eliminate the leakage through the shower head has an extended restricting tubular section depending from a threaded head section. The tubular section extends downwardly more than an inch or so to provide a fluid restriction upward therethrough so that pressure needed to force the water upward through the narrow tubular passage and up through the shower riser is greater than the water pressure exerted through the water pipe to eliminate the leakage through the shower head.
However, these attempts have not been uniformly successful and water leakage can still occur particularly if the water valves are fully opened.
Another problem occurs with turbulence created by the aspirator insert and fitting resulting in noise being transmitted through the pipes in the wall causing reverberation or noise within the confines of the tub alcove.
What is needed is a tub/shower aspirator that will both eliminate leakage through the shower head when water is directed through the tub spout and furthermore reduce noise caused by the flow of water from the water valves through the pipe fitting housing the aspirator.